The objective of this invention is to facilitate the measurement of the blood plasma glucose contents without having to puncture a finger to obtain a blood sample.
Various blood components can be detected by near-Infra Red(IR) beam directed to a finger. The problem is the near impossibility of distinguishing the signal of glucose from the rest of the multidudes of similar signals.
The novel idea of this invention is a practical method to 1) identify the optical absorption band of in vivo glucose by imposing a perturbation in its signal(make it move, thus kinematic) by administering a hypoglycemic drug, e.g., insulin, as well as 2) determine the initial glucose concentration from the rate of decrease of plasma glucose concentration.
This is based on the principle that the rate of transport of the plasma glucose into the cells due to insulin or any hypoglycemic drug is proportional to the initial concentration of the plasma glucose, i.e., the higher the plasma glucose concentration, the faster the transport, and thus the faster disappearance from the plasma(first order kinetic). The signal decrease is measured over a period of time(a few minutes) and the rate is fed into a computer. From the integrated form of this first order kinetic of disappearance, the initial concentration of the insulin-specific glucose is determined.